Ice is extensively used in industry in forms which have been variously defined as flake, crushed or shaved ice, all of which might appropriately be defined as particle-ice. Such ice is used in commerce and industry in various manufacturing processes and food processing plants, including fish, poultry, meat, dairy and other food processing plants, as well as in chemical processing plants, particularly in the die making art, and for precooling concrete where the ice is substituted for water in mixing of cement and aggregates.
Large ice making plants are extensively used in many of the above industries. One example is in dam construction where tons of ice per day are utilized to precool concrete. Such large ice production plants often have ice making machinery producing flake ice 24 hours a day, day in and day out, which ice is stored in large storage facilities of the order of 35 tons up to 500 tons capacity. There are several manufacturers of ice machines capable of producing the flake ice for such storage, one of the better known machines in the United States and throughout the world being made substantially in accordance with U.S. Pat. Nos. 2,735,275 and 2,910,841. Such machines are available commercially in various productive sizes ranging from 5 to 30 tons of ice per 24-hour day. The storage facilities for such ice are generally large insulated and sometimes refrigerated rooms which receive the ice directly from several ice making machines by gravity. Ice can be dispensed at various rates from such large storage facilities varying from dispensing rates of about 8 to 40 tons per hour. The dispensing facilities best known are those made in accordance with U.S. Pat. No. 2,511,246.
In various ice-utilizing industries, small quantities are often required which has given rise to temporary storage facilities which have generally become known as "day tanks". The day tanks are hopper constructed bins which can hold little more than 4,000 pounds of crushed or flake ice and have one or several driven augers in the bottom from which the sides of the bin are sloped outwardly and upwardly in order to feed the ice by gravity to the auger. Attempts to increase ice holding capacity of such day tanks have met with failure due primarily to the greatly increased horsepower required for the auger when a larger tank is attempted to be employed.
Flake and particle-ice have characteristics in storage quite different from other pulverulent materials. Ice may be piled up in a storage room with upright walls, and once the depth of ice is accumulated the walls could be removed and the ice would stand by itself as originally piled. Flake and particle-ice tend to set with pressure, tend to fuse with passage of time, will melt under pressure and fuse upon removal of the pressure and have a tendency to fuse to any metal parts with which it is in contact. Ice thus piled above a quiescent or non-moving auger will tend to fuse to that auger if the depth of the ice is sufficient to create a pressure against the auger flight metal parts. Thus, day tanks larger than about 2 tons capacity have been impractical, yet a need has existed for less than the very large storage tonnage capacity facilities referred to above. Particle-ice referred to occupies about 60 cubic feet per ton (2,000 pounds) of fresh water ice. Such ice that is intended to remain in storage for a period of time before use is generally produced at or near 0.degree. F. and in such form the ice is friable and can be pneumatically conveyed at high velocity through thin wall tubing and flexible rubber hose or by gravity for considerable distances. Various other mechanical conveyors may be used to deliver the ice to a desired point of use, such as augers within tubular enclosures, belts and chain and paddle conveyors.